We propose a multi-center trial in which subjects would be screened for inclusion and exclusion criteria. A primary prevention subgroup will consist of subjects with impaired glucose tolerance (IGT) by National Diabetes Data Group (NDDG) criteria with a fasting plasma glucose (FPG) equal to or more than 110 mg/dl. A secondary intervention subgroup will consist of individuals with NIDDM by NDDG criteria and a FPG < 140 mg/dl. The subjects will been randomized in a 2 x 2 factorial design to: 1) intensive program of diet, exercise and stress reduction versus standard dietary and exercise advice as well as 2) therapy with either glipizide or placebo. We propose that the diet/exercise intervention be modeled after the PATHWAYS program (diet, exercise and stress management) which has been validated as an effective method of weight reduction in inner city African American women. Four thousand individuals would be followed at twenty centers to test whether these interventions can: l) prevent the worsening of glucose tolerance in these subjects over 5 years and 2) reduce cardiovascular morbidity and mortality. We believe our center is uniquely prepared to participate in both the design and execution of this major trial aimed at developing a program that can be easily translated into public health measures to reduce the epidemic of NIDDM and its consequent morbidity and mortality.